Central South America [1], Rainbow boas are widespread throughout much of South America. Brazilian rainbow boas occur in the Amazon Basin, and in coastal Guiana, French Guyana, Suriname and southern Venezuela. [2]

Habitat

Brazilian Rainbow Boas are usually found in very humid tropical forests. Woodland forests, savannas and rain forests. They live in humid woodland forests and can sometimes be found in open savannas. [2]

Characteristics

Size: 4-7 feet [1], about 3 lbs

Longevity: Wild: unknown Captivity: 20-25 years [3] [4]

Physical Description

Brazilian Rainbow boas are so called because of their distinctive iridescent sheen that you can see when their scales catch the light. [1]

Brazilian Rainbow boas are usually red with black markings, with the redness of the snake generally becoming more vibrant with age. [1] Their coloration can be anywhere from brown to red [3]

Their dorsal side is made up of black rings. Within the rings, a lateral orange or reddish crescent stretches across the top, creating the look of eye spots, called ocelli.

The Brazilian rainbow boa is a round-bodied boa of medium build. The head is not particularly large, but it is distinctly wider than the neck. [3]

Boas and pythons, which are more primitive snakes, possess tail/anal spurs, located next to their cloaca.

Dimorphism

There is no obvious secondary sexual characteristic that allow for instant determination of sex, as sizes of individuals can vary greatly. But, in general:

Males: Adult males have substantially larger spurs along the side of the vent and also have noticeably thicker bases of their tails, due to the internal hemipenes [2], than females.

Diet: Carnivore

Nonvenomous constrictor

Diet in the Wild: In the wild the diet consists of rodents, birds, and possibly some forms of aquatic life and lizards. [2]

Diet at the Zoo: 2-3 adult mice every 2 weeks.

Behavior

Nocturnal, night active [5]

Rainbow boas are a primarily terrestrial species of snake [5]. They are ground dwelling, but can sometimes be found climbing on low branches. [1]

Rainbow boas actively search for prey in forest clearings and rocky areas, using heat sensing pits on its jaw to help locate unseen prey [5].

Brazilian rainbow boas are excellent swimmers that avoid hunting in the water, but often hunt for amphibians at the water's edge [5].

Relatively docile temperament when regularly handled, but can be more reactive and prone to bite as juveniles [4] [6].

Reproduction

Ovoviviparous, live-bearing

As with many snakes, sexual maturity is based on length rather than age, but for rainbow boas sexual maturity is usually reached in the first 2.5 to 4 years. Males may breed at four feet and females at 4.5 feet. [3]

Gestation lasts about five months. Neonate (baby) Brazilian rainbows are born live in litters of two to 35. A typical litter contains twelve to 25 babies which are usually 15 to 20 inches long. [2]

In the wild the Rainbow Boa mating season is usually November to January [5]

Neither parent assists or provides parental care of any kind to the hatchlings, who will begin hunting for baby rodents in a week's time [5].

Conservation

Use & Trade: During the 1980s and early 1990s, substantial numbers were exported from Suriname. Today, however, far fewer are exported and most offered for sale are captive bred.[3]

Due to their need for high humidity in a captive environment, they should be considered of intermediate difficulty for snake owners, but as long as that is provided they can thrive in captivity. [6]

Did You Know?/Fun Facts

It is known for its attractive iridescent sheen caused by structural coloration of its scales [6]. The iridescent sheen is imparted by microscopic ridges on their scales, which act like prisms to refract light into rainbows [3].

The Brazilian rainbow boa is one of about 12 named subspecies of rainbow boa. There is, however, much debate about the number of subspecies. [3].

Epicrates cenchria turned out to be more closely related to anacondas (Eunectes) than Caribbean Epicrates (striatus) according to molecular data [7].

Glossary

List of definitions of the most important recurrent technical terms used in the text.

Cloaca - the posterior opening that serves as the only opening for the intestinal, reproductive, and urinary tracts of certain animal species (birds, reptiles, amphibians and some mammals). Also known as vent.

Dorsal - of, on, or relating to the upper side or back of an animal, plant, or organ.

Hemipenes is one of a pair of male reproductive organs, typically held inverted in the animal's abdomen until use during mating.

Ocelli - can be a simple eye, single lens, or false eye spot on an animal. Latin for 'little eye.'

Ovoviviparous - young develop in eggs that are retained by the female (with no placental contact) but hatch inside the body and are born alive.

Spurs - The term spur is sometimes used to describe the pelvic spur, vestigial limbs found in primitive snakes, such as boas and pythons and in the striped legless lizard. The spurs primarily serve as holdfasts during mating. As these form at the terminal end of the limb, they may properly be claws rather than true spurs.

Terrestrial - an animal that lives on the land, rather than primarily in the water (aquatic), trees (arboreal), underground (fossorial), etc.

Vent - see cloaca

Vestigial - refers to genetically determined structures that have apparently lost most or all of their ancestral function in a given species, but have been retained through evolution